1. Field of the Disclosure
The following is directed to abrasive articles, and more particularly bonded abrasive articles having a particularly high amount of porosity.
2. Description of the Related Art
In the production of electronic devices, the back surface of a semiconductor wafer having a plurality of circuits such as IC's and LSI's is ground to a predetermined thickness by a grinding machine before it is divided into individual chips. To grind the back surface of the semiconductor wafer efficiently, a grinding machine equipped with a rough grinding unit and a finish grinding unit is generally used. Generally, the article utilize to conduct the rough grinding process is a bonded abrasive body or bond grindstone, which is obtained by bonding together diamond abrasive grains having a relatively large size with a vitrified bond or metal bond material. A resin bond grindstone having diamond abrasive grains of a median particle size of 2 microns or more contained in a resin bond is typically used for finish grinding operations. Smaller sizes of diamonds generally cannot be utilized in resin bonded articles.
In some cases, the content of the inorganic bonding agent is made relatively high for increasing a grade of the vitrified grindstone and also a degree of strength with which the inorganic bonding agent holds the abrasive grains together. However, such grindstones are not completely satisfactory, having reduced porosity, which can result in difficult or insufficient fracturing and removal of used abrasive grains, leading to relatively easy glazing or clogging of the surface of the vitrified grindstone, chipping of the abrasive structure, poor dressability of the grindstone, and other drawbacks.
The formation of high-porosity grindstones has been disclosed. Generally, high-porosity grindstone bodies are accomplished by the use of foaming agents during forming, which create bubbles and thus porosity in the finally-formed abrasive product.
Still, the industry continues to demand improved grindstone materials, capable of achieving improved grinding performance.